Apart from liquid fuels, the use of gaseous fuels, such as natural gas or hydrogen, for operating vehicles has been increasing lately as well. However, the known injectors are only conditionally suitable for these gaseous fuels, since gaseous fuels have different energy densities and volumes than liquid fuels. To ensure that internal combustion engines operated in this manner do not consume too much fuel, it is necessary to inject the most precise gas quantities possible in each injection. One or more injection process(es) per combustion cycle must also be possible in this context. Apart from the capability of injecting a certain maximum quantity within a predefined period of time, it must also be possible to meter defined minimal gas quantities in a precise manner. Also, low system pressure should prevail during the process, so that the content of a gas tank can be utilized to the fullest extent possible. Furthermore, the injector has to seal the gas from the combustion chamber between the injection processes. FIG. 1 schematically illustrates an example of a known gas injector 1, in which an outwardly opening valve needle 3 sits on a valve seat 2 at a housing 5. FIG. 1 shows the closed state of the injector. When this injector is opened, an effective overall opening cross-section initially becomes linearly larger across the lift, as long as a released annular cross-sectional area at the valve needle constitutes the smallest cross-section. As soon as the annular gap between valve needle 3 having radius R1 and housing 5 has a smaller cross-sectional area than the cross-sectional area between valve seat 2 and housing 5 that is released by the lift, a blow-in rate is constant.
There exists a conflict in objectives between the necessary mass flow rate during an injection and the need for the lowest possible system pressure of the gas in the configuration of gas injectors. This has the result that gas injectors must have the greatest possible flow cross-sections. However, because space is usually limited, the large flow cross-sections are frequently unable to be realized by simple upscaling of the dimensions of the injectors, especially in the case of outwardly opening injectors.